Two distinct restoration approaches boost biocrust development in a post-fire, degraded dryland

Abstract

Non-native grass invasion, human ignitions and expanding land use pressures in the Sonoran Desert, result in loss of vegetation, destabilized soils and slow ecosystem recovery. Biological soil crusts (biocrusts) – thin, coherent soil surface layers, created and inhabited by biota such as cyanobacteria, lichens and mosses – play a critical role in stabilizing soils and supporting ecosystem resilience, yet their potential as active restoration catalysts in post-fire drylands remains underexplored. This study evaluated two biocrust restoration strategies at a fire-affected site in the Tonto National Forest: application of intact strips of farmed biocrusts (sods) and dispersal of gel capsules containing biocrust material, native seeds and diatomaceous earth. Late-successional biocrust cover was eight-fold higher on sod treatments compared to the control and soil stability also increased nearby sods. Capsule treatments produced over 3x higher late-successional biocrust cover than controls in the last season. Seeded plots also supported successful seedling establishment of Baileya multiradiata. Together, these results demonstrate that cultivated biocrust applications can accelerate biocrust recovery, especially for late-successional taxa and increased soil stability in post-fire desert landscapes, offering a nature-based solution to reduce dryland degradation.